A color palette from outside of time & space!
Dark cools for spooky cold scenes, a range of reds and oranges for flesh and creature colors, a good number of dull colors for moody moods, and a few high saturated colors to stand out against it all. Works for any gothic, dark, or moody type of work, had cosmic horror like the Cthulhu Mythos (public domain) in mind myself.
Colors:


Speed paint examples:




Ok, now go draw something spooky or moody!